The present invention relates generally to DC to DC converters, and more particularly, to methods and systems for multi-phase DC to DC conversion.
As microprocessor transistor density increases following Moore's Law, concern grows in the semiconductor industry for powering CPUs reliably and efficiently. Moore's law, surmised by Intel's co-founder Gordon Moore in 1965, predicts that the number of transistors in a single processor will double approximately every two years (“Moore's Law.” par. 4). Intel's latest Dual Core Itanium 2 processor has over one billion transistors.
Powering these processors requires a power supply capable of producing high current output at relatively low voltages. By way of example, the Dual Core Itanium 2 processor requires 1.0875 volts DC to 1.25 volts DC from the power supply with a maximum current input of 121 amperes and a maximum total power of about 177 W.
Further, the International Technology Roadmap for Semiconductors (ITRS) produced by the Semiconductor Industry association (SIA) predicts that microprocessors will operate at 0.6 volts DC and 300 amperes by the year 2010. As a result, computer power supplies must evolve to meet the future demands of future microprocessors.
The typical computer power rail of the system board provides 12 volts DC. The 12 volts DC rail voltage is then converted to the specified processor voltage without incurring a large power loss within the converter circuitry. Therefore, DC-to-DC converters have become the norm for powering microprocessors. However, as processor voltage ratings decrease and current ratings increase, the challenge to produce a converter that will supply the proper power, without sacrificing efficiency and output quality, becomes more difficult.
In view of the foregoing, there is a need for an improved multi-phase DC-to-DC converter circuit aimed at improving the delivery of power to a microprocessor. Such an improved multi-phase DC-to-DC converter circuit topology will improve the output voltage and current characteristics while also improving overall converter efficiency.